One of the advantages of pigment-dyeing textiles is the economy of the process. Thus there is also a saving of water and/or energy. Dyeing can be carried out by padding the textile fabric simply followed by a drying and a polymerization to ensure bonding of the pigment material to the fiber.
Processes of this type can be used for the coloration of fibers and mixtures of fibers of various types. The absence of any need for affinity between the pigment material and the fibers, permits the process to be used for the dyeing of the most varied mixtures of fibers with uniform totality and reproducability. In all cases, the bonding between the pigment material and the fibers is not a function of chemical affinity between the pigment material and the fibers, but rather a bonding effect brought about by a bonding agent which is applied together with the pigment as part of the dyeing composition. It is no longer necessary to wash the fabric extensively, a considerable economic saving over other dyeing processes.
The pigment used for the dyeing of textile fabrics according to earlier processes comprise, as essential ingredients, a colored pigment insoluble in water, and a binder capable of fixing the pigment to the fibrous support.
It is common practice to use as the binder, emulsions of polymers or copolymers, generally acrylate or alkylmethacrylate copolymers, styrene-acrylate and/or alkylmethacrylate copolymers, butadiene-acrylate, styrene-butadiene, and styrene-butadiene-acrylate copolymers, terpolymers, etc.
These diverse products are capable of providing a latex in which the coloring agent is dispersed and which can be used to bond the coloring agent to fibers which may have no affinity whatsoever to the coloring agent or pigment.
In the aforementioned copending application and in French application No. 74 27 662, there are described new compounds which can be added to synthetic-resin latexes and characterized by a thermal sensitivity, especially by their ability to cause coagulation and activation of the latex under predetermined conditions upon an increase in temperature. In other words, the aforedescribed application provides thermosensitive latex compositions which can be activated at predetermined temperatures.
Other thermally coagulatable latexes have also been described in the literature. In general, they are intended to serve as bonding agents for nonwoven fabrics and even for the formation of thin-wall or small-thickness molded bodies.
With respect to latexes which contain pigments, it has been found that conventional compositions permit migration of the pigment from the surface which is coated toward the opposite surface, usually with increasing temperature, giving rise to irregular coloration, poor cutting, the so-called double-face effect and like phenomena. Because of migration of pigments to the surface of the textile material, the finished article has a poor resistance to wear of the color applied.